Actuator for leveler control mechanism



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Q. Q .0 mm Q Q John Gui-left HTTYS Aug. 25, 1959 R. A. GURRIES ETALACTUATOR FOR LEVELER CONTROL MECHANISM mea'se z. 17. 1957 Aug. 25, 1959R. A. GURRIES ETAL ACTUATOR FOR LE VELER CONTROL MECHANISM Filed Sept.17, 1957' 2 Sheets-Sheet INVENTORS Rf]. G'urries John CurZeZ'Z HTTYSACTUATOR FOR LEVELER CONTROL MECHANISM Raymond A. Gurries, San Jose, andJohn Curlett, Los Gatos, Caliii, assignors to Gurries Manufacturing Co.,San Jose, Calif., a corporation of California Application September 17,1957, Serial No. 684,481

6 Claims. (Cl. 37-180) This invention relates to ground levelingmachines, and particularly to the longitudinal-level controlled actuatorfor a leveler of the type shown in Patent No. 2,792,- 651, granted May21, 1957, to H. W. Hobday.

The purpose and specific functioning of the actuator as shown in thepatent above noted, is set forth in said patent. It was found that inoperation, however, the actuator as constructed was subject to rapidwear, since all bearing points were exposed and could not easily bemaintained in a properly lubricated condition. Also, the valve of theactuator assembly was a separate entity from the actuating mechanism,and could not well be made or enclosed as a unit therewith.

The principal object of the present invention is to improve and simplifythe construction and operation of the actuator, and to arrange theoperating parts so that they are all enclosed in compact unitary form ina dirt-proof and tamper-proof manner, and so that no adjustments areever required, and proper lubrication ceases to be a problem.

Another object of the invention is to provide a valve unit for theactuator which comprises a proportionalporting servo valve actuated upondeviation of the leveler from a proper level, and a positivecam-operating lock valve, controlled by rotation of the tail boom of theleveler about a vertical axis.

This arrangement is an improvement over the single valve of the previousstructure in that it allows a more sensitive control and movement of theservo valve to be obtained than was previously the case.

It is also an object of the invention to provide a practical, reliable,and durable actuator for level control mechanism, and one which will beexceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings:

Fig. 1 is a fragmentary side outline of a land leveler showing the sameequipped with the improved actuator.

Fig. 2 is an enlarged sectional elevation of the actuator detached andshowing the servo valve closed and the lock valve in its normal openposition.

Fig. 3 is a fragmentary sectional plan on line 33 of Fig. 2.

Fig. 4 is a fragmentary sectional elevation, in the plane of Fig. 2,showing the lock valve control cam turned, and the valve in a lockedposition.

Referring now more particularly to the drawings, and to the charactersof reference marked thereon, the leveler to which the improved actuatoris applied comprises a main rigid frame structure 1, which-intermediateits ends-supports a blade and bowl unit 2. Transversely spaced wheels 3,mounted for vertical adjustment relative to the frame structure, aredisposed just rearwardly of the unit 2; adjustment of the wheels beingice accomplished by means of hydraulic rams 4, as shown and described inthe aforementioned Patent No. 2,792,651.

A tail boom 5 projects rearwardly from the frame structure 1, beingconnected thereto, as at 6, for relative swivel movement in a verticalplane and for independent relative swivel movement in a horizontal planeand about a vertical axis, as at 7, as shown in said patent.

The rams 4 are actuated to relatively raise or lower the wheels 3 uponrelative swivel movement of the tail boom 5 in a vertical plane, and areheld inactive upon relative swivel movement of the tail boom in ahorizontal plane a predetermined amount from a normal in-line positionwith the main frame, regardless of any accompanying swivel movement in avertical plane.

The improved actuator by means of which the above recited ram action isobtained comprises a housing 8. This housing includes a lower mainportion or member 9 which is rigidly secured on a bracket 10' supportedon the frame structure 1 at its rear end and overhanging the tail boomconnections, as shown in Fig. 1.

The housing 8 includes a top dome 11 seated on top of the housingportion 9, and swivelly mounted thereon, for rotation about a verticalaxis on a neck 12 on the upper end of said main housing portion 9. Thedome is held against removal from said portion 9 by a collar 13 securedthereon and engaging the base flange 14 of the dome.

Secured in the dome 11 concentric therewith, and depending therefrominside the housing, is a shaft 15; the housing 8 being mounted on thebracket 10 so that said shaft is coaxial with the axis of horizontalswivel movement of the tail boom, as indicated in Fig. 1.

A sleeve 16 is slidable on the shaft, said sleeve adjacent its upper endbeing formed with a forwardly projecting horizontal slot 17. A cross pin18 rides in this slot; said pin being mounted on the outer end of a yoke19 which straddles the sleeve and is fixed on a transverse shaft 20journaled in the dome 11 rearwardly of the sleeve 16.

A lever 21 projects rearwardly from and is secured on shaft 20. Apush-pull rod 22 is connected to and depends from lever 21 and dependsto operative connection with a bracket 23 on the tail boom, as shown inthe aforementioned patent, in such a manner that when the tail boomswivels vertically, the lever 21 is raised or lowered, and when the tailboom swings horizontally the lever 21and dome 11-are likewise swunghorizontally or about a vertical axis.

The sleeve 16 at its lower end carries an enlarged fiat head 24 whoseunder surface engages the upper end of an L-shaped rocker arm 25turnably mounted intermediate its ends on a cross shaft 26 mounted inthe lower housing portion 9. At its lower end the rocker arm is providedwith a cross pin 27 which somewhat loosely rides in a vertical slot 28formed in the adjacent end of the plunger or spool 29 of the servo valveunit of the actuator. This spool extends horizontally or at right anglesto the shaft 15 and slides in a sleeve 30 secured in the housing member9.

The sleeve 30 is formed on the outside with a pair of longitudinallyspaced, circumferential grooves 31 and 32 with a similarly disposedcentral groove 33, and since the sleeve is surrounded by the metal ofhousing memher 9, said grooves form in effect enclosed passages orchambers.

A plurality of relatively small, circ-umferentially and axially spacedports 34 connect the groove chambers 31 and 32 with the interior of thesleeve 30. Ports or passages 35 and 36 lead through the housing member 9from chambers 31 and 32, respectively, and are connected A somewhatheavy compression spring 39 extends lengthwise of spool 29, hearing atone end against the end of sleeve 30 furthest from the rocker arm 25,and at the other end against a retainer 40 mounted on a stem 41 rigidwith, and projecting from, the adjacent end of the spool 29.

Above the servo valve and parallel to the spool 29 is the spool 42 ofthe lock valve; said spool being slidable in a sleeve 43 fitted in, andmainly surrounded by, the metal of the housing member 9.

The sleeve is formed on the outside with circumferential longitudinallyspaced grooves 44 and 45 which form enclosed chambers. Ports 46 and 47provide communication between chambers 44 and 45, respectively, and theinterior of the sleeve.

A passage 48 leads from chamber 44 to the exterior of the housing member9 for connection to a branched conduit (not shown) leading to and fromthe rams 4, while a passage 49 connects chambers 45 and 33. The spool 42includes a land 50 arranged in one position of the spool to uncover theports 47, as shown in Fig. 2, and another position of said spool tocover or close said ports, as shown in Fig. 4. In either position of thespool the ports 46 remain open or uncovered.

Secured on the shaft in horizontal alinement with the spool 42 is a camdisc 51 engaged on its periphery by a sleeve-guided ball 52 which alsoengages the adjacent end of said spool; said spool extending radially ofthe shaft 15.

A compression spring 53 engages the opposite end of the spool 42 andacts to hold the ball in engagement with the spool and cam disc. The camdisc is formed on its periphery with a wide-angle V-notch 54, as shownin Fig. 3, in which the ball 52 seats under normal operating conditions,or when the tail boom andthe main frame of the leveler are in straightlongitudinal alinement. Under such conditions the ports 47 are uncoveredor open, as shown in Fig. 2. When the shaft 15 and the cam disc rotate acertain arcuate amount, the ball is shifted out of the notch 54 and thespool 42 is correspondingly retracted to the position shown in Fig. 4,in which the ports are closed.

In operation, it will be seen that upon relative swinging of the mainframe and tail boom in a vertical plane, the lever 21 will becorrespondingly swung or rocked about the shaft 20. The yoke 19 willalso be swung and the sleeve 16 will be moved up or down the shaft 15.This will cause the rocker arm 25 to turn on its shaft 26, thus shiftingthe spool 29 of the servo valve in one direction or the other so as tosuccessively uncover one set or the other of the ports 34.

The fluid is thus free to flow between either chamber 31 or 32 and thechamber 44 of the lock valve sleeve and thence to or from rams 4 throughpassage 48 and the connected conduits of the hydraulic system, throughport 37, chamber 33, port 49, chamber 44, and ports 47 and 46.

This flow is on the assumption that the lock valve is open, as is thecase when the ball 52 is seated in the cam notch 54, and the land 50 ofthe spool 42 is shifted toward the shaft 15 to uncover the ports 47.This condition will obtain while the frame and tail boom of the levelerare in longitudinal alinement, and also with a relative rotation of theframe and tail boom about a vertical axis an amount insufiicient torotate the cam disc so as to entirely retract the ball 52 from the camnotch 54. The rams can thus be actuated even though the tail boom may beout of line to a relatively small degree.

When the ball is completely clear of the cam notch, however, the spool42 is shifted so as to completely cover the ports 47, as shown in Fig.4. As long as the spool is in this position therefore, the flow of fluidto or from the rams is completely shut off, regardless of any movementof the spool 29' of the servo valve.

The use of a number of separate small ports 34 in each set, practicallyoverlapping each other in a direction axially of the spool, has beenfound to give a better and more sensitive flow control than is the casewhen a single elongated port is used.

It will be noted that the housing, including the dome, forms anoil-tight enclosure, so that all parts therein are protected and may bekept submerged in oil so that wear is reduced to a minimum.

It will also be observed that the construction and arrangement of partswithin the housing is such that no adjustments of any such part is evernecessary.

From the foregoing description it will be readily seen that there hasbeen produced such a device as will substantially fulfill the objects ofthe invention, as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new anduseful, and upon which Letters Patent are desired:

1. An actuator for the hydraulic level control rams interposed in theconduit system of a land leveler, said actuator comprising a housingadapted to be mounted on the leveler and including a fixed lower memberand a dome mounted on said member for rotation about a vertical axis, ashaft concentric and fixed with the dome depending into the lower memberof the housing, a rearwardly projecting lever pivoted on the dome forswinging movement in a vertical plane and turnable as a unit with thedome about said vertical axis, a sleeve slidable on the shaft, meansbetween the lever and sleeve to shift the latter along the shaft uponswinging of the lever in a vertical plane, a servo valve in the lowermember of the housing and adapted to be interposed in the conduit systemto control the flow of fluid to and from the rams, means between thesleeve and servo valve to actuate the latter upon vertical movement ofthe sleeve, a normally open lock valve mounted in the lower member ofthe housing and adapted to be interposed in the conduit system betweenthe servo valve and the rams, and means between the shaft and lock valveto close the latter upon rotation of the shaft a predetermined arouateamount.

2. A structure, as in claim 1, in which the servo valve includes anaxially movable spool disposed in a plane at right angles to the shaftand said actuating means comprises a generally L-shaped rocker armdisposed in the housing in a vertical plane, a transverse pivot supportfor the rocker arm intermediate its ends, the arm below the supportbeing substantially vertical, an enlarged head on the lower end of thesleeve, the upper end of the rocker arm engaging the head, and a pivotconnection between the lower end of the rocker arm and one end of thespool.

3. A structure, as in claim 2, in which the rocker arm engages the underside of the head, and a spring acting on the spool tending to shift thesame lengthwise in a direction to maintain the rocker arm in contactwith the head.

4. A structure, as in claim 1, in which the lock valve includes anaxially movable spool disposed radially of the shaft, and a springurging the spool toward the shaft; the valve closing means comprising acam disc on the shaft disposed in the horizontal plane of the spool,said disc having a peripheral notch therein, and a noncompressibleelement engaging the end of the spool adjacent the disc and seated insaid notch 'When the valve is open and disengageable from the notch uponrotation of the disc so as to 0211156 an axial movement in a valveclosing direction to be imparted to the spool.

5. A structure, as in claim 4, in which the element is a ball, withretaining means for the ball included with the valve to prevent lateraland vertical shifting of the ball.

6. A structure, as in claim 4, in which the element is a ball, and thenotch is of wide-angle V-form.

UNITED STATES PATENTS Temple Mar. 5, 1935 Buchanan Oct. 16, 1945 MeusyNov. 10, 1953 Ross Feb. 19, 1957 Hobday May 21, 1957 FOREIGN PATENTSCanada Nov. 11, 1952 Great Britain June 2, 1954

